Chill a rocks or highball glass and fill it with ice.
Add rum and horchata. Stir to combine.
Top with a dash of cinnamon.
Notes
You can use store bought horchata or you can make Homemade Horchata.For more vanilla flavor - use Vanilla Infused Rum. Note - the nutrition information is not complete because my program did not have horchata, so I manually entered a calorie count.